Is the nystagmus consistent each time you test Dix Hallpike or move into the first position of CRM and do reported symptoms match what you see? With an 80 year old neck you may have some difficulty getting good canal positioning and perhaps with a concussion you might have some protective posturing that prevents good movement through the CRM. Is the concussive person motion sensitive on top of having episodic positional vertigo? Likely you just need to be persistent with trying either the Epley or Modified Semont Maneuvers to get a positive result. If symptoms aren’t matching what you see or your findings aren’t consistent I’d revisit your assessment and ensure you are treating posterior canal BPPV.
Ryan

Bernadette: My initial thoughts are to continue canalith repositioning as you have been doing. Perhaps more restrictive positioning after the procedure may help. Some of my more challenging patients have done better if I had them avoid the involved side when sleeping after the procedure or having them sleep in a recliner chair if they could do so. One other thought is possibly having the patient do self treatment. One of my more challenging BPPV patients would demonstrate some improvement for a few days after treatment and then the vertigo would re-occur. I taught this patient to do a home Epley treatment which helped to resolve his BPPV along with my clinic treatment. You do have to make sure that the patient is able to correctly follow the home instructions and fortunately this patient was able to do so. I hope these ideas are of some help to you. Tom

How many trials of CRM are you performing with each patient during a visit and if you are performing more than 1 maneuver what is the response ind DH on 2nd trial? Are any other nystagmus patterns present after upbeating torsional nystagmus in DH and does the torsional upbeating nature completely fatigue at the 20 second mark you indicate?